Cookie cutter character archetypes, no really, a lot of manga being produced now have characters that are so unbelievably generic, trying their hardest to copy other characters in a 1:1 fashion. And to add an extension to that, the most generic looking male MC's that are made of cardboard because it's "supposed to be a wish fullfillment fantasy for the reader" or some other nonsense like that. This trend chasing, take no risks, safe & generic, probably think-tanked by a robot to satisfy the highest ratio gross revenue to effort garbage is destroying artistic creation & it needs to stop. It ain't just a problem for manga, it seems to be an issue surrounding entertainment as a whole.
Love triangles that aren't actually love triangles. I don't get this, why are most "love triangle" manga labeled as such when they aren't love triangles? Sorry but I don't acknowledge the following formula being representative of a love triangle:
Person A > Person B
Person C > Person B
No really, there are 3223 different manga/manhwa/manhua on mangaupdates with the tag, and I can assure you, that most of them follow the formula above. What I consider to be a love triangle is as follows:
Person A > Person B
Person B > Person C
Person C > Person A
"Strong female lead" main characters, let me explain, it isn't the character itself I have a problem with, it's the male lead that follows if the story either has romance as a main plot or a minor plot, the issue then becomes 1 of 2 things. 1, "strong female lead" gets downgraded into useless nitwit that needs the male lead to save them all the damn time. 2, the male lead(s) devolves into nothing but a whimpering melodramatic purse puppy that is more akin to a pet than a love interest. Why can't we just have both strong leads without the obligatory, incredibly forced savior arc, that, regardless of who has the leading role, the other character in distress always appears to be written OOC or the plot has to reach really hard to put that character in that situation and you're sat there thinking, well, this is bullshit. This only come across as disrespectful to the character and I don't know how to describe how I feel about it. It's like when you have a cross-over between 2 different shonen series and these 2 main characters who are considered bad-asses in their own respective universes, get into a fight, except, there's just one problem; in one corner, you got your high school delinquent with a chip on his shoulder, and in the other corner, you have this dude who is literally an ultra-godlord god-slaying, multi-universal busting doomslayer, and they have to make the fight look even so it just feels like you're watching a grown-ass adult who injects steroid recreationally, play pretend fighting with make-a-wish special needs toddler and try to convincingly lose.